LOVE the radio-it was not as easy to get set up as I originally thought and I had to make many emails back and forth to work out some kinks. The manual and install instructions are not as 'robust' as I needed so I had some snags along the way, but the email communication and customer support were fantastic. With the company being in a different time zone, there was some delay by a few hours to get info, but they never disappointed to solve the issue. I ended up having to remove a nut on the back of the unit in order to get the GPS/WIFI antenna to fit. Its a VERY tight fit on the avalanche and I am guessing its similar with all GMC's in that body style (I have an 07) Once installed and set up this thing is awesome. Sounds MUCH better than my factory head unit, and the navigation features are amazing. I haven't tried out any of the other features, but I assume they are just as good-I recommend the Apple Play connection if you have an iphone....well worth the upgrade! It was a harder install than I thought, and I wish I would have gotten a pro to install. I saved the money but invested many more hours than I wanted. I'd be happy to offer suggestions and my advice to anyone looking at this unit. Contact the company for my contact info-Giving a 4 instead of 5 based only on the problems that I had with the install...they could have been resolved with info prior to purchase, but overall this thing is great! Contact me for specific info on the install if you need to know some work arounds.